Organic Materia (Not A Rock Or Mineral)

Ethiopian Fire Opal

Hydrated Silica (SiO2·nH2O)

Granite

Phaneritic Acidic Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)

Sedimentary Breccia

Breccia (Clastic Sedimentary Rock)

Quartz with Hematite Staining

Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3) inclusions

Pyrite

Pyrite (Iron Disulfide), FeS2

Granite

Granite (composed primarily of Quartz SiO2, Alkali Feldspar KAlSi3O8, and Plagioclase)

Almandine Garnet

Almandine (Fe3Al2(SiO4)3)

Turquoise

Turquoise (Hydrated phosphate of copper and aluminium), CuAl6(PO4)4(OH)8·4H2O

Chlorastrolite (Greenstone)

Chlorastrolite (variety of Pumpellyite) - Ca2(Mg,Fe)Al2(SiO4)(Si2O7)(OH)2 · H2O

Quartz

Quartz (SiO₂)

Granite

Phaneritic Felsic Igneous Rock

Sandstone (Ferruginous)

Arenite with Iron oxide staining (SiO2 with Fe2O3)

Geode with Iron-Stained Quartz/Calcite

Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) in Sedimentary Matrix

Granite

Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).

Black Sand (Magnetite Sand)

Magnetite-rich Placers (Fe3O4)

Dalmatian Stone

Dalmatian Jasper (Aphanitic Igneous Rock with Arfvedsonite inclusions)

Gneiss

High-grade metamorphic rock (Gneiss)

Green Aventurine

Quartz variety (SiO2 with inclusions)

Chert (specifically Gray Chert)

Silicon Dioxide (SiO2)

Chert / Flint (with Crinoid Stem Molds)

Microcrystalline Quartz (SiO2)

Sandstone

Arenite (primarily SiO2)

Quartz Geode (partially formed/chalcedony with iron staining)

Quartz (SiO2) with Chalcedony (cryptocrystalline quartz) and likely Iron Oxides/Hydroxides

Granite

Granite (Phaneritic Acidic Igneous Rock)

Red Jasper

Microcrystalline Quartz (SiO2) with Hematite impurities

Vesicular Basalt (Iron-Stained)

Mafic Volcanic Rock (Basalt)

Amethyst on Agate/Basalt Matrix

Silicon Dioxide (SiO2) with iron impurities

Quartz Pebble

Quartz (Silicon Dioxide - SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Diamond

Diamond (Pure Carbon, C)

Almandine Garnet

Almandine (Fe3Al2Si3O12)

Hematite

Iron(III) oxide (Fe2O3)

Quartzite River Cobble

Quartzite (primarily SiO2)

Geode (Unopened)

Silica-rich Concretion (primarily SiO2)

Sandstone

Arenite (primarily composed of SiO2 - Silicon Dioxide)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Sedimentary/Metamorphic Matrix

Granite

Granite (Felsic Plutonic Rock)

Granite

Granite (Felsic Plutonic Rock)

Tiger's Eye

SiO2 (Silicon Dioxide with inclusions of Goethite/Limonite)

Stromatolite (Fossiliferous Limestone)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Quartz (Druzy or Geode fragment)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)